The potential diagnostic benefit of repeated troponin I measurements following high-intensity exercise

Abstract

Objectives: Myocardial stress increases troponin levels after exercise in individuals with and without coronary artery disease. This study investigates whether maximal or prolonged high-intensity exercise affects post-exercise cardiac troponin I (cTnI) levels in well-trained individuals with stable revascularised coronary artery disease (Revasc-CAD) compared to those without obstructive coronary artery disease (Wo-CAD).

Design: Observational study.

Methods: CTnI levels were measured pre-, 3- and 24-h post-exercise in 15 middle-aged Revasc-CAD and 22 Wo-CAD individuals. Participants underwent a maximal cardiopulmonary exercise test and three high-intensity interval spinning sessions with increasing durations of 20, 40, and 60 min, at one-week intervals.

Results: Following exercise, cTnI levels peaked at 3 h, with significant reduction at 24 h (p < 0.001). The highest cTnI levels were observed after the 60-minute session (p = 0.001). There were no differences in cTnI levels between the two groups following high-intensity exercise or increased exercise duration. In contrast, there was no reduction in cTnI between 3 and 24 h after maximal exercise in the Revasc-CAD group. During the study, a progressive post-exercise cTnI elevation was observed following exercise in a participant with in-stent stenosis. He had normal resting cTnI levels but demonstrated increasing post-exercise cTnI during progression of the coronary artery obstruction.

Conclusions: High-intensity exercise of varying durations caused similar cTnI elevations in Revacs-CAD and Wo-CAD groups, but maximal exercise resulted in prolonged cTnI elevation in Revasc-CAD individuals. Progressive post-exercise cTnI increases in a participant with in-stent restenosis highlight the potential value of repeated post-exercise cTnI assessments for detecting evolving coronary artery obstruction.

Keywords: Cardiac biomarkers; Coronary artery disease; Coronary artery obstruction; Exercise duration; Exercise testing; Timing of troponin assessment.